Sorry you're stuck but there's almost always a pretty easy fix! Do NOT try to start all over again, eg. uninstall Max's Pitch Package, etc. That can make things worse.
Before you post make sure you check the Help FAQ for an instant solution first. Then, if you can't find it there, you can post your problem here and we'll get to it ASAP (within 24 hours), but be sure you:
post in the right category
INCLUDE AT LEAST ONE SCREENCAP IN YOUR POST TO SHOW THE PROBLEM!!!!!!!!
explain the problem clearly
I've been trying to start Lab 1b and have purchased the Max Pitch Package twice successfully. Once I get to the page where it tells me to to sign into SF, it always gives me this error message. I have reset my password several times and can't log in on the page that is displayed after purchase. However, I'm able to sign in with the same credentials on a separate browser.
OK, I'll try today within the next hour.
Try an incognito or private window.
We will reimburse you for extra payments. Don’t worry.